JP2018512772A - Fast radio link control error recovery with low latency transmission - Google Patents

Abstract

Methods, systems, and devices for communication are described. A fast error recovery procedure may be used that reduces latency for radio link control (RLC) data packet recovery during low latency operation. The device may detect a failed low latency transmission and activate a timer associated with the failed transmission. The device may generate a failure report if the failed transmission is not rescheduled, for example if the timer expires before rescheduling. The failure report may be sent to the RLC entity of the device or the medium access control (MAC) layer entity of the scheduler. In some cases, the device may maintain a list of unterminated transmissions for high priority bearers. [Selection] Figure 4

Description

Cross-reference of related applications

  [0001] This patent application filed US patent application Ser. No. 15 / 054,637 by Vajapeyam et al. Entitled “Fast Radio Link Control Error Recovery with Low Latency Transmissions” filed on Feb. 26, 2016, and 2015. Claims priority to US Provisional Patent Application No. 62 / 127,179 by Vajapeyam et al. Entitled "Fast RLC Error Recovery with Low Latency Transmissions" filed March 2, Assigned to the assignee.

  [0002] The following relates generally to wireless communications, and more specifically to fast radio link control (RLC) error recovery with low latency transmission. Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be able to support communication with multiple users by sharing available system resources (eg, time, frequency, and power). Examples of such multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems (eg, Long Term Evolution (LTE® system). A wireless multiple-access communication system can include a number of base stations, each supporting communication for multiple communication devices simultaneously, which can also be known as user equipment (UE).

  [0003] An RLC error recovery procedure can be used by a device to recover from a transmission failure by determining whether a set of data packets has been received correctly and in the desired order. In some cases, the transmitting device may assign a sequence number (SN) to the set of data packets. The receiving device may start a reordering timer if data packets are received in an out of order. Upon expiration of the reordering timer, the receiving device sends a status report to the transmitting device indicating that no data packet has been received, and the transmitting device may schedule a retransmission. However, the time delay for the RLC error recovery process to schedule retransmissions may not be suitable for low latency communication.

  [0004] A device may use a fast error recovery procedure that reduces latency for Radio Link Control (RLC) data packet recovery during low latency operation. The device may detect a failed low latency transmission and activate a timer associated with the failed transmission. If the timer expires before the failed transmission is rescheduled, the device may generate a failure report. The failure report may be sent to the RLC entity, Packet Data Convergence Protocol (PDCP) entity, or Medium Access Control (MAC) entity of the receiving device, transmitting device, or scheduler. In some cases, the device is non-terminated, such as active hybrid automatic repeat request (HARQ) processing for high priority bearers (eg, bearers associated with low latency data). ) Can maintain a list of transmissions.

  [0005] A method of wireless communication is described. The method detects a transmission error at a receiving device based at least in part on a state of HARQ processing, starts a timer based at least in part on detection of the transmission error, and for HARQ processing. Determining that the timer has expired before a grant for the retransmission of the data is received and reporting a transmission error to the transmitting device based at least in part on the determination.

  [0006] An apparatus for wireless communication is described. An apparatus includes: a means for detecting a transmission error based at least in part on a state of HARQ processing; a means for starting a timer based at least in part on detection of a transmission error; Means for determining that the timer has expired before a grant for the retransmission of the data is received, and means for reporting a transmission error to the transmitting device based at least in part on the determination.

  [0007] A further apparatus is described. The apparatus can include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may cause the processor to detect a transmission error based at least in part on the state of the HARQ process at the receiving device, start a timer based at least in part on detection of the transmission error, and HARQ. To determine that the timer has expired before a grant for retransmission for processing is received and to cause the transmitting device to report a transmission error based at least in part on the determination It may be operable.

  [0008] A non-transitory computer readable medium for wireless communication is described. The non-transitory computer readable medium is for the processor to detect a transmission error at the receiving device based on the status of the HARQ process, to start a timer based on the detection of the transmission error, and for the HARQ process. Instructions may be included for determining that the timer has expired before a grant for the retransmission of the first time is received and for causing the transmitting device to report a transmission error based on the determination.

  [0009] In some examples of the methods, apparatus, or non-transitory computer readable media described above, reporting a transmission error may indicate that the receiving device is in error to an RLC entity, PDCP entity, or MAC entity of the transmitting device. Comprising sending an indication.

  [0010] Some examples of the methods, apparatus, or non-transitory computer readable media described above further comprise sending an error indication to an entity of the transmitting device using contention based resources. May include processing, features, means, or instructions for sending an action.

  [0011] Some examples of the methods, apparatus, or non-transitory computer readable media described above may further include a process, feature, means, or instruction for maintaining a list of unfinished transmissions, wherein So reporting transmission errors is based on the list.

  [0012] In some examples of the methods, apparatus, or non-transitory computer readable media described above, each entry in the list is mapped to a time index.

  [0013] In some examples of the methods, apparatus, or non-transitory computer readable media described above, reporting a transmission error comprises sending a bitmap corresponding to the list to the transmitting device.

  [0014] In some examples of the method, apparatus, or non-transitory computer readable medium described above, the list is limited to a set of high priority HARQ processes, where the HARQ process is a high priority It is an element of a set of HARQ processes.

  [0015] In some examples of the methods, apparatus, or non-transitory computer readable media described above, the set of high priority HARQ processes is determined based on a latency mode of operation.

  [0016] Some examples of the method, apparatus, or non-transitory computer readable medium described above are further for identifying a new data indicator (NDI) for HARQ processing prior to timer expiration. It may include processing, features, means, or instructions, where reporting transmission errors is based on NDI.

  [0017] Some examples of the method, apparatus, or non-transitory computer readable medium described above may further include a process, feature, means, or instruction for selecting a fast recovery mode, where a timer Starting is based on the selection.

  [0018] In some examples of the methods, apparatus, or non-transitory computer readable media described above, the selection is based on a latency mode of operation.

  [0019] In some examples of the methods, apparatus, or non-transitory computer readable media described above, the selection is based on the configuration of at least one high priority bearer.

  [0020] Some examples of the method, apparatus, or non-transitory computer readable medium described above are further a process, feature, means, or for sending a negative acknowledgment (NACK) based on the status of the HARQ process. Instructions can be included.

  [0021] Some examples of the methods, apparatus, or non-transitory computer readable media described above are further for maintaining a set of transport blocks in a buffer for a minimum time period for retransmission. A process, feature, means, or instruction may be included.

  [0022] Aspects of the present disclosure are described with reference to the following drawings.

6 illustrates an example wireless communication system that supports fast RLC error recovery with low latency transmission in accordance with various aspects of the disclosure. 6 illustrates an example wireless communication system that supports fast RLC error recovery with low latency transmission in accordance with various aspects of the disclosure. 4 illustrates an example channel structure that supports fast RLC error recovery with low latency transmission in accordance with various aspects of the disclosure. FIG. 4 illustrates an example process flow for a system that supports fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. FIG. 7 illustrates a block diagram of a wireless device that supports fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. FIG. 7 illustrates a block diagram of a wireless device that supports fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. FIG. 7 illustrates a block diagram of a wireless device that supports fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. 6 illustrates a system including a UE that supports fast RLC error recovery with low latency transmission according to various aspects of the disclosure. 6 illustrates a system including a base station that supports fast RLC error recovery with low latency transmission in accordance with various aspects of the disclosure. 6 illustrates a method for fast RLC error recovery with low latency transmission according to various aspects of the disclosure. 6 illustrates a method for fast RLC error recovery with low latency transmission according to various aspects of the disclosure. 6 illustrates a method for fast RLC error recovery with low latency transmission according to various aspects of the disclosure. 6 illustrates a method for fast RLC error recovery with low latency transmission according to various aspects of the disclosure. 6 illustrates a method for fast RLC error recovery with low latency transmission according to various aspects of the disclosure. 6 illustrates a method for fast RLC error recovery with low latency transmission according to various aspects of the disclosure.

Detailed description

  [0031] In accordance with this disclosure, a device may use a fast error recovery procedure to reduce latency for radio link control (RLC) data packet recovery during low latency operation. Aspects of the present disclosure are described in the context of a wireless communication system. For example, the device may select a fast error recovery mode for a component carrier associated with low latency data and activate a timer to facilitate the data recovery process. In some examples, the fast error recovery mode may reduce data recovery after a negative acknowledgment (NACK) versus negative acknowledgment (ACK) error. These and other aspects of the present disclosure are further illustrated by and described with reference to device diagrams, system diagrams, and flowcharts relating to fast error recovery mode.

  [0032] FIG. 1 illustrates an example wireless communication system 100 for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) / LTE-Advanced (LTE-A) network.

  [0033] Base station 105 may communicate wirelessly with UE 115 via one or more base station antennas. Each base station 105 may provide communication coverage for a respective geographic coverage area 110. The communication link 125 shown in the wireless communication system 100 may include an uplink (UL) transmission from the UE 115 to the base station 105 or a downlink (DL) transmission from the base station 105 to the UE 115. Base stations 105 can support fast recovery procedures and communicate with each other. For example, the base station 105 may interface with the core network 130 through the backhaul link 132 (eg, S1, etc.). Base stations 105 may also communicate with each other over backhaul link 134 (eg, X1, etc.) either directly or indirectly (eg, through core network 130). Base station 105 may perform scheduling and radio configuration for communication with UE 115, or may operate under the control of a base station controller (not shown). In various examples, the base station 105 may be a macro cell, a small cell, a hot spot, and so on. Base station 105 may also be referred to as eNode B (eNB) 105 in some examples.

  [0034] The UEs 115 are distributed throughout the wireless communication system 100, and each UE 115 may be fixed or mobile. UE 115 may also be called a mobile station, a subscriber station, a remote unit, a wireless device, an access terminal, a handset, a user agent, a client, or some other suitable terminology. The UE 115 may also be a cellular phone, a wireless modem, a handheld device, a personal computer, a tablet, a personal electronic device, a machine type communication (MTC) device, and so on. UE 115 may communicate with base station 105 and support fast recovery procedures.

  [0035] A UE may be configured with multiple carriers in a carrier aggregation (CA) configuration, and the communication link 125 may represent such a multi-carrier CA configuration. A carrier may also be referred to as a component carrier (CC), layer, channel, etc. The term “component carrier” refers to each of a plurality of carriers utilized by a UE in CA operation and may differ from other portions of the system bandwidth. For example, the CC may be a relatively narrow bandwidth carrier that can be utilized independently of or in combination with other component carriers. Each CC may provide the same capabilities as a separate carrier based on Release 8 or Release 9 of the LTE standard. Multiple component carriers can be utilized or aggregated simultaneously to provide greater bandwidth and, for example, higher data rates to several UEs 115. From this, individual CCs may be backward compatible with legacy UEs 115 (eg, UEs 115 implementing LTE Release 8 or Release 9), but other UEs 115 (eg, LTE versions after Release 8/9) The implementing UE 115) may be configured with multiple component carriers in multi-carrier mode. A carrier used for DL may be referred to as a DL CC, and a carrier used for UL may be referred to as a UL CC. UE 115 may be configured with multiple DL CCs and one or multiple UL CCs for carrier aggregation. Each carrier may be used to transmit control information (eg, reference signal, control channel, etc.), overhead information, data, etc.

  [0036] UE 115 may communicate with a single base station 105 using multiple carriers, or may communicate with multiple base stations 105 simultaneously on different carriers. Each cell of base station 105 may include a UL CC and a DL CC. The coverage area 110 of each serving cell for the base station 105 can be different (eg, CCs on different frequency bands can experience different path loss). In some examples, one carrier is designated as a primary carrier for UE 115, or a primary component carrier (PCC), which can be served by a primary cell (PCell). The primary cell may be configured semi-statically by an upper layer (for example, radio resource control (RRC), etc.) for each UE. Certain uplink control information (UCI), eg, ACK / NACK, channel quality indicator (CQI), and scheduling information transmitted on the physical uplink control channel (PUCCH) is carried by the PCell. Additional carriers may be designated as secondary carriers or secondary component carriers (SCC), which may be served by a secondary cell (SCell). Similarly, the SCell can be semi-statically configured for each UE. In some cases, the secondary cell may not contain the same control information as the primary cell or may not be configured to transmit it.

  [0037] In some cases, the wireless communication system 100 may utilize one or more extended component carriers (eCC). An eCC may be characterized by one or more features including flexible bandwidth, different transmission time intervals (TTI), and modified control channel configurations. In some cases, an eCC may be associated with a dual connectivity configuration or a CA configuration (eg, when multiple serving cells have suboptimal backhaul links). The eCC may also be configured for use with shared spectrum or unlicensed spectrum (eg, where more than one operator is authorized to use the spectrum). An eCC characterized by flexible bandwidth may be utilized by a UE 115 that prefers to use limited bandwidth (eg, to save power) or that cannot monitor the entire bandwidth One or more segments may be included.

  [0038] In some cases, an eCC may utilize a different TTI length than other CCs, which may include the use of reduced or variable symbol durations compared to other CC TTIs. The symbol duration may remain the same in some cases, but each symbol may represent a different TTI. In some examples, the eCC may include multiple hierarchical layers associated with different TTI lengths. For example, a TTI in one hierarchical layer may correspond to a uniform 1 ms subframe, whereas in a second layer, a variable length TTI may correspond to a burst of short duration symbol periods. In some cases, shorter symbol durations can also be associated with increased subcarrier spacing. In conjunction with the reduced TTI length, eCC may utilize dynamic time division duplex (TDD) operation (ie, eCC switches from DL operation to UL operation for short bursts according to dynamic conditions). Can make it possible).

  [0039] Flexible bandwidth and variable TTI may be associated with a modified control channel configuration (eg, eCC may utilize an enhanced physical downlink control channel (ePDCCH) for DL control information). For example, one or more control channels of an eCC may utilize frequency division multiplexing (FDM) scheduling to accommodate flexible bandwidth usage. Other control channel modifications include control channels transmitted at different intervals, or (for example, to indicate the length of variable-length UL and DL bursts, or evolved multimedia broadcast multicast service (eMBMS) scheduling). Including the use of additional control channels. The eCC may also include modified or additional hybrid automatic repeat request (HARQ) related control information. UE 115 may operate on eCC and other CCs using discontinuous reception.

  [0040] The wireless communication system 100 may operate on multiple layers. The two lowest layers may include a medium access control (MAC) or data link layer and a physical (PHY) layer. The wireless communication system 100 may also include an RLC layer that connects higher layers (eg, Radio Resource Control (RRC) layer and Packet Data Convergence Protocol (PDCP) layer) to lower layers (eg, MAC layer). . The RLC entity in base station 105 or UE 115 may ensure that the transmitted packets are organized into appropriately sized blocks (corresponding to the MAC layer transport block size). If an incoming data packet (ie, PDCP or RRC service data unit (SDU)) is too large for transmission, the RLC layer may segment the data packet into several smaller RLC protocol data units (PDUs). If the incoming data packets are too small, the RLC layer may concatenate some of them into a single larger RLC PDU. Each RLC PDU may include a header that contains information on how to reassemble the data. The RLC layer may also ensure that the packet is transmitted reliably. The transmitter maintains a buffer of indexed RLC PDUs and can continue retransmitting each PDU until a corresponding ACK is received. In some cases, the transmitter sends a polling request to determine which PDU has been received, and the receiver can respond with a status report. Unlike the MAC layer HARQ function, the RLC automatic repeat request (ARQ) may not include forward error correction (FEC).

  [0041] The RLC entity may operate in one of three modes: an acknowledged mode (AM), an unacknowledged mode (UM), and a transparent mode (TM). In AM, an RLC entity may perform segmentation / concatenation and ARQ. This mode may be appropriate for delay tolerant or error sensitive transmissions. In UM, an RLC entity may perform segmentation / concatenation but may not perform error recovery. This may be appropriate for delay sensitive or error tolerant traffic (eg, Voice over LTE (VoLTE)). TM performs only data buffering and does not include either concatenation / segmentation or ARQ. The TM can be used primarily to send broadcast control information (eg, master information block (MIB) and system information block (SIB)), paging messages, and RRC connection messages. Some transmissions may be sent without RLC (eg, random access channel (RACH) preamble and response).

  [0042] At the MAC layer, HARQ may be a method to ensure that data is received correctly over the wireless communication link 125. HARQ may include a combination of error detection (eg, using cyclic redundancy check (CRC)), FEC, and retransmission (eg, ARQ). HARQ may improve throughput at the MAC layer in poor radio conditions (eg, signal to noise conditions). Incremental Redundancy HARQ (Incremental Redundancy HARQ) allows the incorrectly received data to be stored in a buffer and combined with subsequent transmissions to improve the overall possibility of successfully decoding the data. . In some cases, redundant bits may be added to each message prior to transmission. This can be particularly useful in poor conditions. In other cases, redundant bits are not added to each transmission, but are retransmitted after the sender of the original message receives a NACK indicating an unsuccessful attempt to decode the information.

  [0043] Thus, base station 105 and UE 115 may use multiple recovery procedures to correct transmission failures. For example, the RLC entity may be configured to operate with RLC-AM and schedule retransmissions for data packets that are not correctly received by UE 115. The RLC recovery process can operate at a slower rate than the MAC recovery process and can be used to mitigate errors missed by the MAC process. For example, ACK / NACK errors associated with HARQ processing, physical downlink control channel (PDCCH) erasure, etc.

  [0044] The RLC of the transmitting device may assign a sequence number (SN) to each PDU (ie, data packet) in the set of PDUs according to the order in which they should be received by the UE 115. The PDUs can then be moved to the MAC layer where they can be segmented and rearranged into transport blocks. The transport block can then be associated with the corresponding HARQ process and sent to the UE 115. The receiver may reassemble them at the MAC layer of UE 115. The transport block may be sent to the UE's RLC entity, where UE 115 may determine the SN of each data packet. The SN can be used to determine whether data packets have been received in the proper order. For example, the receiving device starts a reordering timer when a data packet with a higher order SN: SN (n + 1) is received before a data packet with a lower order sequence number: SN (n) Yes. For example, the receiver may use the identified data packet to update the state variable VR (H), which is equal to (highest received SN) +1 and VR (R), which is Equal to (SN received in-order) +1. If VR (H)> VR (R), the receiver may detect that the SN (ie, data packet) is missing and start a reordering timer (it may be based on the HARQ retransmission protocol) ). At the expiration of the reordering timer, the receiving device sends a status report to the transmitting device indicating that the data packet SN (n) has not been received, and the transmitting device therefore transmits the missing data packet SN (n). A retransmission can be scheduled.

  [0045] The RLC recovery process may introduce latency into the communication link. For example, the UE 115 may not detect a missing SN (eg, SN (n)) until a subsequent SN (eg, SN (n + 1)) is correctly received. UE 115 may also wait until the reordering timer expires before sending a status report to base station 105. Further, UE 115 may send an SR and wait for base station 105 to schedule a transmission window for the status report.

  [0046] For example, a delay may occur after a HARQ error. That is, the UE 115 may fail to receive the transport block associated with the data packet: SN1. After unsuccessful transmission, UE 115 may transmit a NACK to base station 105. However, the base station 105 may detect NACK as an ACK incorrectly and continue to transmit subsequent transport blocks for data packet: SN1. Accordingly, the RLC receiver of UE 115 may fail to receive an expected retransmission for the failed transport block and thus may fail to successfully receive a data packet that includes the transport block. The UE may then wait until a subsequent data packet (eg, data packet: SN2, SN3, etc.) is successfully received before determining that SN1 was not received in the proper order. This type of error can be referred to as a NACK vs. ACK error, so the RLC recovery procedure can take 20 ms or more to detect.

  [0047] The delay associated with the RLC recovery process may not be suitable for a particular latency mode of operation (eg, low latency operation, very low latency operation). For example, low latency operation can accommodate a delay as low as 1 ms. Moreover, a shorter TTI that can be utilized by low latency communication can reduce the reliability of the control channel and increase the error probability for the transport block. As a result, the recovery procedure becomes more frequent during low latency operation, and as a result, the latency for the communication link may increase accordingly. Thus, a device such as base station 105 or UE 115 may use a fast error recovery procedure to reduce latency for RLC data packet recovery during low latency operation. The device may select a fast error recovery mode for CCs associated with low latency data and activate a timer (shorter than the RLC reordering timer) to facilitate the data recovery process. If the timer expires before the failed transmission is rescheduled, the device may generate a failure report. The failure report may be sent to the receiving device, transmitting device, or scheduler, RLC entity, PDCP entity, or MAC entity. Fast error recovery mode may reduce data recovery after a NACK vs. ACK error or other transmission error.

  [0048] FIG. 2 illustrates an example wireless communication system 200 for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. The wireless communication system 200 may include a UE 115-a and a base station 105-a, which may be examples of the UE 115 or base station 105 described above with reference to FIG. Base station 105-a and UE 115-a may communicate with each other via downlink 205 when UE 115-a is within coverage area 110-a, as generally described above with reference to FIG. UE 115-a may send ACK / NACK to base station 105-a via uplink 210, generally as described above with reference to FIG.

  [0049] UE 115-a may receive a set of transport blocks from base station 105-a via downlink 205. In some cases, the transport block may include low latency data. (For example, the transport block may be sent over eCC using reduced TTI.) UE 115-a may select the fast recovery mode for the bearer associated with the low latency transport block. UE 115-a may maintain a list of all unterminated transmissions and monitor the status of unterminated transmissions for a configurable time window. In some examples, the transmission that has not been terminated may be an active HARQ process or a transport block. In some cases, the UE 115-a may fail to decode the transport block and send a NACK over the uplink 210 to the base station 105-a. UE 115-a may simultaneously start a timer 215 associated with the failed transport block. The timer 215 may be integrated with the UE 115-a (eg, the timer may be a module within the processor of the UE 115-a). In some cases, the timer 215 may expire before the failed transport block is rescheduled by the base station 105-a and a reporting procedure may be triggered. The reporting procedure may include sending a failure report to the base station 105-a indicating which unfinished transmission has failed. In some cases, the failure report may additionally include information about other unfinished transmissions in the list for which the associated timer 215 has not expired.

  [0050] In some examples, the UE 115-a may fail the base station 105-a so that the base station 105-a (eg, at the MAC layer) can determine which transmissions should be rescheduled. You can send a report. In another example, the UE 115-a's MAC entity may inform the UE 115-a's RLC entity of potential problems with low latency (and therefore potentially high priority) bearers. The RLC entity can then trigger an early SN status report to the base station 105-a so that the base station 105-a can determine which data packets should be rescheduled. In other examples, the UE 115-a may allow the base station 105-a entity (eg, an RLC entity, a PDCP entity, or the base station 105-a to determine which data packets should be rescheduled. An error indication may be sent to the MAC entity.

  [0051] In another example, the base station 105-a may similarly utilize a fast error recovery mode. For example, during a UL transmission, the MAC entity of base station 105-a may detect an error, start the timer, and generate an error report if the timer expires prior to receiving the UL transmission. In one example, the error is reported to the RLC entity of the base station. In some examples, the MAC entity of base station 105-a may provide a failure report directly to the scheduler of base station 105-a to request a retransmission from UE 115-a. In another example, the PDCP entity of base station 105-a may provide a failure report directly to the scheduler of base station 105-a to request a retransmission from UE 115-a.

  [0052] FIG. 3 illustrates an example channel structure 300 for fast RLC error recovery with low latency transmission in accordance with various aspects of the disclosure. Channel structure 300 may illustrate aspects of low latency transmission between UE 115 and base station 105, as described above with reference to FIGS. 1-2.

  [0053] In some examples, UE 115 may receive transport block 305 and may fail to decode it. The data in the transport block 305 may be associated with HARQ process: HARQ1, data packet: SN1, and may be the nth retransmission: RV (N). UE 115 may detect the failed transmission, update the list of unterminated transmissions with the entry associated with transport block 305, and start timer 340. Later or simultaneously, UE 115 may send a NACK to base station 105. In some cases, a NACK may be misinterpreted as an ACK at the base station 105 in a NACK to ACK error 310. HARQ1 may therefore schedule a subsequent transport block 315 with a new data transmission, RV (0), but UE 115 may expect a retransmission of the data in transport block 305 sell. Timer 340 may continue to run until either UE 115 identifies that the data in transport block 305 has been rescheduled or until timer 340 expires. Since the data in transport block 305 has not been rescheduled, UE 115 detects an error and informs base station 105 that the transmission of data in transport block 305 has failed (eg, at the expiration of timer 340). Failure report 320 may be sent to the base station 105 entity. Base station 105-a may use failure report 320 to reschedule the data in transport block 305 for re-transmission in transport block 305-a. In some cases, UE 115 may successfully receive the retransmission in transport block 305-a and send ACK 325 to base station 105. In some cases, the UE 115 may determine that the first data packet was successfully received at the indicator 330 and the state variables VR (H) and VR (R) are 2 (or last received successfully). Updated to be equal to SN). At a later time, UE 115 may determine that the second data packet was successfully received at indicator 335 and state variables VR (H) and VR (R) may be updated again.

  [0054] Under the RLC recovery protocol, the wireless network may not detect a NACK to ACK error 310 for a long time period (eg, a time period that is incompatible with low latency communication), and the data packet: SN1 The transmission can be unsuccessful. Thus, the state variable value in indicator 330 may not change (ie, VR (H) and VR (R) are equal to 1). At a later time, UE 115 may successfully receive a second data packet at indicator 335 and state variable VR (H) may be equal to 3, but VR (R) is equal to 1. sell. This satisfies the condition VR (H)> VR (R), and the UE 115 may start the reordering timer 345. Upon expiration of the reordering timer, the RLC transmitter of UE 115 sends a status report alerting base station 105 that data packet: SN1 has not been received, and base station 105 sends a retransmission for data packet: SN1. Can be scheduled. The difference between the reordering timer 345 endpoint (not shown) and the timer 340 endpoint illustrates a portion of the delay associated with the RLC recovery procedure that may be reduced using the fast error recovery procedure. sell.

  [0055] FIG. 4 illustrates an example process flow 400 for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. Process flow 400 may be performed by UE 115-b and base station 105-b, which may be an example of UE 115 or base station 105, as described above with reference to FIGS. In some examples, UE 115-b may monitor transmissions that have not been terminated and activate a timer for failed transmissions. If the timer expires, UE 115-b may send a failure report requesting rescheduling of the failed transmission.

  [0056] In step 405, the UE 115-b may select a fast recovery mode. In some examples, the selection is based on low latency operation. In some examples, the selection is based on the configuration of at least one high priority bearer. In some examples, the selection is based on MAC signaling or RRC signaling.

  [410] UE 410-b may receive one or more transport blocks from base station 105-b. In some cases, the transport block may include low latency data that may be delay sensitive. In some cases, base station 105-b may maintain a set of transport blocks in the buffer for a minimum time period for retransmission.

  [0058] At 415, UE 115-b may detect a transmission error. In some cases, UE 115-b may detect a transmission error based on the state of HARQ processing. For example, the transport block may not be received correctly.

  [0059] At 420, UE 115-b may respond to base station 105-b with an ACK / NACK for the received transport block. For example, a NACK may be sent for a transport block that was not received correctly. From this, UE115-b can transmit NACK based on the state of a HARQ process. In some cases, the HARQ response may be affected by transmission or reception errors.

  [0060] In some cases, UE 115-b may maintain a list of unterminated transmissions. UE 115-b may update the list based on the received transport block. In some cases, the list may be maintained by the MAC layer of UE 115-b. In some examples, each entry in the list is mapped to a time index. In some examples, the list is limited to a set of transport blocks or high priority HARQ processes, which may be based on low latency operation. In some cases, UE 115-b may maintain an unterminated transmission state in the list for a configurable window.

  [0061] At 425, UE 115-b may start a timer based on detection of a transmission error. The timer may be based on a fast error recovery mode.

  [0062] At 430, UE 115-b may generate an error report based on determining that the timer has expired before a grant for retransmission for HARQ processing is received.

  [0063] At 435, UE 115-b may report a failure, for example, by indicating which HARQ process or transport block was not successfully received. In some examples, reporting the transmission error includes sending an error indication to the RLC entity, PDCP entity, or MAC entity of base station 105-b. In some examples, reporting the transmission error includes sending an error indication to the scheduling device entity. In some examples, reporting a transmission error includes sending a bitmap corresponding to the list. In some examples, UE 115-b may identify a new data indicator (NDI) for HARQ state prior to timer expiration and report a transmission error. In some examples, transmission errors are reported prior to receiving the next RLC PDU. In some cases, sending the failure report may include sending an RLC status report based on the error indication. In some examples, sending the RLC status report includes sending an error indication (eg, to the entity of base station 105-b) using contention based resources. In some examples, sending the error indication includes sending the error indication (eg, to the entity of base station 105-b) using contention based resources.

  [0064] At 440, the base station 105-b may schedule retransmissions for failed transmissions. At 445, the base station 105-b can transmit a second set of transport blocks, which can include a scheduled retransmission.

  [0065] FIG. 5 shows a block diagram of a wireless device 500 configured for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. Wireless device 500 may be an example of the aspects of base station 105 or UE 115 described with reference to FIGS. 1-4. The wireless device 500 may include a receiver 505, a fast RLC error recovery module 510, or a transmitter 515. Wireless device 500 may also include a processor. Each of these components can be in communication with each other.

  [0066] The receiver 505 may control information, user data, or packets associated with various information channels (eg, control channel, data channel, and information related to fast RLC error recovery with low latency transmission, etc.). Such information can be received. Information may be communicated to the fast RLC error recovery module 510 and other components of the wireless device 500.

  [0067] The fast RLC error recovery module 510 detects a transmission error based on the state of the HARQ process, starts a timer based on the detection of the transmission error, and retransmits for the HARQ process. Determining that the timer has expired before receiving the grant, and reporting a transmission error based on the determination.

  [0068] The transmitter 515 may transmit signals received from other components of the wireless device 500. In some examples, transmitter 515 may be collocated with receiver 505 in a transceiver module. The transmitter 515 may include a single antenna or may include multiple antennas. In some examples, the transmitter 515 may send an RLC status report (eg, to the transmitting device entity) based on the error indication. In some examples, sending the RLC status report includes sending an error indication (eg, to the transmitting device entity) using contention-based resources.

  [0069] FIG. 6 shows a block diagram of a wireless device 600 for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. Wireless device 600 may be an example of aspects of wireless device 500, base station 105, or UE 115 described with reference to FIGS. 1-5. The wireless device 600 may include a receiver 505-a, a fast RLC error recovery module 510-a, or a transmitter 515-a. The wireless device 600 may also include a processor. Each of these components can be in communication with each other. The fast RLC error recovery module 510-a may also include an error detection module 605, an error detection timing module 610, a report trigger module 615, and an error reporting module 620.

  [0070] The receiver 505-a may receive information that may be communicated to the fast RLC error recovery module 510-a and to other components of the wireless device 600. The fast RLC error recovery module 510-a may perform the operations described herein with reference to FIG. Transmitter 515-a may transmit signals received from other components of wireless device 600.

  [0071] The error detection module 605 may detect a transmission error based on the state of the HARQ process, as described herein with reference to FIGS. 2-4.

  [0072] The error detection timing module 610 may start a timer based on detection of a transmission error, as described herein with reference to FIGS. 2-4.

  [0073] The report trigger module 615 may determine that the timer has expired before a grant for retransmission for HARQ processing is received, as described herein with reference to FIGS. 2-4.

  [0074] The error reporting module 620 may report a transmission error (eg, to an entity of the transmitting device) based on the determination, as described herein with reference to FIGS. 2-4. In some examples, transmission errors may be reported prior to receiving the next RLC PDU.

  [0075] FIG. 7 illustrates a block of a fast RLC error recovery module 510-b that may be a component of the wireless device 500 or wireless device 600 for fast RLC error recovery with low latency transmission in accordance with various aspects of the disclosure. A diagram 700 is shown. Fast RLC error recovery module 510-b may be an example of aspects of fast RLC error recovery module 510 described with reference to FIGS. 5-6. The fast RLC error recovery module 510-b may include an error detection module 605-a, an error detection timing module 610-a, a report trigger module 615-a, and an error reporting module 620-a. Each of these modules may perform the functions described herein with reference to FIG. The fast RLC error recovery module 510-b may also include an RLC reporting module 705, a MAC reporting module 710, a transmission list module 715, an NDI detection module 720, a fast recovery mode selector 725, and a transport block buffer 730.

  [0076] The RLC reporting module 705 may report a transmission error as described herein with reference to FIGS. 2-4 to transmit, receive, or scheduler, RLC entity, PDCP entity. Or sending error indications to the MAC entity.

  [0077] The MAC reporting module 710 may report sending a transmission error may include sending an error indication to the MAC entity of the scheduling device, as described herein with reference to FIGS. 2-4. Can be configured.

  [0078] Transmission list module 715 may maintain a list of unterminated transmissions and report transmission errors may be based on the list, as described herein with reference to FIGS. 2-4. In some examples, each entry in the list may be mapped to a time index. In some examples, reporting a transmission error includes sending a bitmap corresponding to the list. In some examples, the list is limited to a set of high priority HARQ processes, which may be an element of a set of high priority HARQ processes. In some examples, the set of high priority HARQ processes may be determined based on low latency operation.

  [0079] The NDI detection module 720 may identify the NDI for HARQ processing prior to timer expiration and report transmission errors as described herein with reference to FIGS. Based on

  [0080] The fast recovery mode selector 725 may select a fast recovery mode and start a timer, as described herein with reference to FIGS. 2-4, based on the selection. In some examples, the selection may be based on a latency operation mode (eg, low latency operation, very low latency mode). In some examples, the selection may be based on the configuration of at least one high priority bearer. In some examples, the selection may be based on MAC signaling or RRC signaling.

  [0081] The transport block buffer 730 may maintain a set of transport blocks in the buffer for a minimum time period for retransmission, as described herein with reference to FIGS. 2-4. .

  [0082] FIG. 8 shows a diagram of a system 800 that includes a UE 115-c configured for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. System 800 can include UE 115-c, which can be an example of wireless device 500, wireless device 600, or UE 115 described herein with reference to FIGS. The UE 115-c may include a fast RLC error recovery module 810, which may be an example of the fast RLC error recovery module 510 described with reference to FIGS. 5-7. The UE 115-c may also include a HARQ response module 825. UE 115-c may also include components for two-way voice and data communications, including a component for sending communications and a component for receiving communications. For example, UE 115-c may communicate bi-directionally with base station 105-c or UE 115-d.

  [0083] The HARQ response module 825 may send an acknowledgment (eg, an ACK / NACK response) based on the status of the HARQ process, as described herein with reference to FIGS. 2-4.

  [0084] The UE 115-c may also include a processor 805 and memory 815 (including software (SW) 820), a transceiver 835, and one or more antenna (s) 840, each of which It may communicate with each other (eg, via bus 845) directly or indirectly. Transceiver 835 may communicate bi-directionally with one or more networks via antenna (s) 840 or wired or wireless links, as described above. For example, the transceiver 835 can communicate bi-directionally with the base station 105 or another UE 115. Transceiver 835 may include a modem for modulating packets, providing the modulated packets to antenna (s) 840 for transmission, and demodulating packets received from antenna (s) 840. . UE 115-c may include a single antenna 840, but UE 115-c may also have multiple antennas 840 that are capable of transmitting or receiving multiple wireless transmissions simultaneously.

  [0085] The memory 815 may include random access memory (RAM) and read only memory (ROM). Memory 815, when executed, includes computer readable, computer executable software that includes instructions that, when executed, cause processor 805 to perform various functions described herein (eg, fast RLC error recovery with low latency transmission, etc.). / Firmware code 820 may be stored. Alternatively, software / firmware code 820 may not be directly executable by processor 805 but may cause a computer to perform the functions described herein (eg, when compiled and executed). The processor 805 may include an intelligent hardware device (eg, a central processing unit (CPU), microcontroller, ASIC, etc.).

  [0086] FIG. 9 shows a diagram of a system 900 that includes a base station 105-d configured for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. System 900 can include a base station 105-d, which can be an example of wireless device 600, wireless device 700, or base station 105 described herein with reference to FIGS. 1, 2, and 6-8. . Base station 105-d may include a base station fast RLC error recovery module 910, which may be an example of the base station fast RLC error recovery module 910 described with reference to FIGS. 6-8. Base station 105-d may also include components for two-way voice and data communication, including a component for transmitting communication and a component for receiving communication. For example, base station 105-d may communicate bi-directionally with base station 105-e, base station 105-f, UE 115-e, or UE 115-f.

  [0087] In some cases, the base station 105-d may have one or more wired backhaul links. Base station 105-d may have a wired backhaul link (eg, an S1 interface, etc.) to core network 130. Base station 105-d may also communicate with other base stations 105 such as base station 105-e and base station 105-f via an inter-base station backhaul link (eg, an X2 interface). Each of the base stations 105 may communicate with UE 115 using the same or different wireless communication technologies. In some cases, base station 105-d may communicate with other base stations such as 105-e or 105-f utilizing base station communication module 925. In some examples, the base station communication module 925 may provide an X2 interface within LTE / LTE-A wireless communication network technology to provide communication between some of the base stations 105. In some examples, base station 105-d may communicate with other base stations through core network 130. In some cases, base station 105-d may communicate with core network 130 through network communication module 930.

  [0088] Base station 105-d may include a processor 905, memory 915 (including software (SW) 920), transceiver 935, and antenna (s) 940, each of which (eg, bus system 945). (Through) communication with each other, either directly or indirectly. Transceiver 935 may be configured to communicate bi-directionally with UE 115 via antenna (s) 940, which may be a multi-mode device. The transceiver 935 (or other components of the base station 105-d) may also be configured to communicate bi-directionally with one or more other base stations (not shown) via the antenna 940. Transceiver 935 may include a modem configured to modulate the packet, provide the modulated packet to antenna 940 for transmission, and demodulate the packet received from antenna 940. Base station 105-d may include a plurality of transceivers 935, each with one or more associated antennas 940. A transceiver may be an example of the combined receiver 505 and transmitter 515 of FIG.

  [0089] The memory 915 may include RAM and ROM. When executed, the memory 915 also causes the processor 910 to perform various functions described herein (eg, select fast RLC error recovery with low latency transmission, coverage enhancement techniques, call processing, database management, messages, etc. Computer-readable, computer-executable software code 920 including instructions configured to perform routing, etc.) may be stored. Alternatively, software 920 may not be directly executable by processor 905, but may be configured to cause a computer to perform the functions described herein, for example, when compiled and executed. The processor 905 can include intelligent hardware devices such as a CPU, microcontroller, ASIC, and the like. The processor 905 may include various special purpose processors such as encoders, queue processing modules, baseband processors, wireless head controllers, digital signal processors (DSPs), and the like.

  [0090] Base station communication module 925 may manage communication with other base stations 105. The communication management module may include a scheduler or a controller for controlling communication with the UE 115 in cooperation with other base stations 105. For example, the base station communication module 925 can coordinate scheduling for transmission to the UE 115 for various interference mitigation techniques such as beamforming or joint transmission.

  [0091] The components of wireless device 500, wireless device 600, fast RLC error recovery module 510-b, system 800, and system 900 are each individually or collectively some of the functions applicable in hardware. It may be implemented using at least one application specific integrated circuit (ASIC) adapted to perform any or all of them. Alternatively, the functions may be performed by one or more other processing units (or cores) on at least one integrated circuit (IC). In other examples, other types of integrated circuits (eg, structured / platform ASIC, field programmable gate array (FPGA), or another semi-custom IC) may be used, which may be any known in the art Can be programmed. The functionality of each unit can also be implemented in whole or in part by instructions embodied in memory and formatted to be executed by one or more general purpose or special purpose processors.

  [0092] FIG. 10 shows a flowchart illustrating a method 1000 for fast RLC error recovery with low latency transmission in accordance with various aspects of the disclosure. The operations of method 1000 may be implemented by a device such as UE 115 or base station 105, or components thereof, as described with reference to FIGS. 1-9. For example, operation of method 1000 may be performed by fast RLC error recovery module 510 as described with reference to FIGS. 5-8. In some examples, the device may execute a set of codes to control functional elements of the device to perform the functions described below. In addition or alternatively, the device may perform the aspect functions described below using special purpose hardware.

  [0093] At block 1005, the device may detect a transmission error at the receiving device based on the status of the HARQ process, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1005 may be performed by error detection module 605, as described herein with reference to FIG.

  [0094] At block 1010, the device may start a timer based on detection of a transmission error, as described herein with reference to FIGS. 2-4. In certain examples, the operation of block 1010 may be performed by error detection timing module 610, as described herein with reference to FIG.

  [0095] At block 1015, the device may determine that the timer has expired before a grant for retransmission for HARQ processing is received, as described herein with reference to FIGS. 2-4. . In one particular example, the operation of block 1015 may be performed by a report trigger module 615, as described herein with reference to FIG.

  [0096] At block 1020, the device may report a transmission error based on the determination to the transmitting device, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1020 may be performed by error reporting module 620, as described herein with reference to FIG.

  [0097] FIG. 11 shows a flowchart illustrating a method 1100 for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. The operations of method 1100 may be implemented by a device such as UE 115 or base station 105, or components thereof, as described with reference to FIGS. 1-9. For example, the operations of method 1100 may be performed by fast RLC error recovery module 510, as described with reference to FIGS. 5-8. In some examples, the device may execute a set of codes to control functional elements of the device to perform the functions described below. In addition or alternatively, the device may perform the aspect functions described below using special purpose hardware. The method 1100 may also incorporate aspects of the method 1000 of FIG.

  [0098] In block 1105, the device may detect a transmission error based on the status of the HARQ process at the receiving device, as described herein with reference to FIGS. 2-4. In certain examples, the operation of block 1105 may be performed by error detection module 605, as described herein with reference to FIG.

  [0099] At block 1110, the device may start a timer based on detection of a transmission error, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1110 may be performed by an error detection timing module 610, as described herein with reference to FIG.

  [0100] At block 1115, the device may determine that the timer has expired before a grant for retransmission for HARQ processing is received, as described herein with reference to FIGS. 2-4. . In one particular example, the operation of block 1115 may be performed by a report trigger module 615, as described herein with reference to FIG.

  [0101] At block 1120, the device may report a transmission error based on the determination to the transmitting device, as described herein with reference to FIGS. 2-4. In some cases, reporting a transmission error includes sending an error indication to a transmitting device, receiving device, or scheduler, RLC entity, PDCP entity, or MAC entity. In one particular example, the operation of block 1120 may be performed by error reporting module 620, as described herein with reference to FIG.

  [0102] At block 1125, the device may send an RLC status report based on the error indication, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1125 may be performed by a transmitter 515 as described herein with reference to FIG.

  [0103] FIG. 12 shows a flowchart illustrating a method 1200 for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. The operations of method 1200 may be implemented by a device such as UE 115 or base station 105, or components thereof, as described with reference to FIGS. 1-9. For example, the operations of method 1200 may be performed by fast RLC error recovery module 510 as described with reference to FIGS. 5-8. In some examples, the device may execute a set of codes to control functional elements of the device to perform the functions described below. In addition or alternatively, the device may perform the aspect functions described below using special purpose hardware. Method 1200 may also incorporate the methods 1000 and 1100 aspects of FIGS. 10-11.

  [0104] At block 1205, the device may detect a transmission error based on the status of the HARQ process at the receiving device, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1205 may be performed by error detection module 605, as described herein with reference to FIG.

  [0105] At block 1210, the device may start a timer based on detection of a transmission error, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1210 may be performed by error detection timing module 610, as described herein with reference to FIG.

  [0106] At block 1215, the device may determine that the timer has expired before a grant for retransmission for HARQ processing is received, as described herein with reference to FIGS. 2-4. . In certain examples, the operation of block 1215 may be performed by report trigger module 615, as described herein with reference to FIG.

  [0107] At block 1220, the device may report a transmission error based on the determination, as described herein with reference to FIGS. 2-4. In some cases, reporting the transmission error includes sending an error indication to the MAC entity of the scheduling device. In one particular example, the operation of block 1220 may be performed by error reporting module 620, as described herein with reference to FIG.

  [0108] FIG. 13 shows a flowchart illustrating a method 1300 for fast RLC error recovery with low latency transmission in accordance with various aspects of the disclosure. The operations of method 1300 may be implemented by a device such as UE 115 or base station 105, or components thereof, as described with reference to FIGS. 1-9. For example, the operations of method 1300 may be performed by fast RLC error recovery module 510, as described with reference to FIGS. 5-8. In some examples, the device may execute a set of codes to control functional elements of the device to perform the functions described below. In addition or alternatively, the device may perform the aspect functions described below using special purpose hardware. The method 1300 may also incorporate aspects of the methods 1000, 1100, and 1200 of FIGS. 10-12.

  [0109] At block 1305, the device may maintain a list of unterminated transmissions and reporting transmission errors may be based on the list, as described herein with reference to FIGS. 2-4. . In one particular example, the operation of block 1305 may be performed by a transmission list module 715, as described herein with reference to FIG.

  [0110] At block 1310, the device may detect a transmission error based on the status of the HARQ process, as described herein with reference to FIGS. 2-4. In certain examples, the operation of block 1310 may be performed by error detection module 605, as described herein with reference to FIG.

  [0111] In block 1315, the device may start a timer based on detection of a transmission error, as described herein with reference to FIGS. 2-4. In certain examples, the operation of block 1315 may be performed by error detection timing module 610, as described herein with reference to FIG.

  [0112] At block 1320, the device may determine that the timer has expired before a grant for retransmission for HARQ processing is received, as described herein with reference to FIGS. 2-4. . In one particular example, the operation of block 1320 may be performed by report trigger module 615, as described herein with reference to FIG.

  [0113] At block 1325, the device may report a transmission error based on the determination, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1325 may be performed by error reporting module 620, as described herein with reference to FIG.

  [0114] FIG. 14 shows a flowchart illustrating a method 1400 for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. The operations of method 1400 may be implemented by a device such as UE 115 or base station 105, or components thereof, as described with reference to FIGS. 1-9. For example, the operations of method 1400 may be performed by fast RLC error recovery module 510, as described with reference to FIGS. 5-8. In some examples, the device may execute a set of codes to control functional elements of the device to perform the functions described below. In addition or alternatively, the device may perform the aspect functions described below using special purpose hardware. The method 1400 may also incorporate aspects of the methods 1000, 1100, 1200, and 1300 of FIGS. 10-13.

  [0115] At block 1405, the device may detect a transmission error based on the status of the HARQ process, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1405 may be performed by error detection module 605, as described herein with reference to FIG.

  [0116] At block 1410, the device may start a timer based on detection of a transmission error, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1410 may be performed by error detection timing module 610, as described herein with reference to FIG.

  [0117] In block 1415, the device may identify the NDI for the HARQ state prior to timer expiration, as described herein with reference to FIGS. 2-4. In certain examples, the operation of block 1415 may be performed by NDI detection module 720, as described herein with reference to FIG.

  [0118] At block 1420, the device may determine that the timer expired before a grant for retransmission for HARQ processing was received, as described herein with reference to FIGS. 2-4. . In one particular example, the operation of block 1420 may be performed by report trigger module 615, as described herein with reference to FIG.

  [0119] At block 1425, the device may report a transmission error based on the decision, and reporting the transmission error may be based on the NDI, as described herein with reference to FIGS. 2-4. . In one particular example, the operation of block 1425 may be performed by error reporting module 620, as described herein with reference to FIG.

  [0120] FIG. 15 shows a flowchart illustrating a method 1500 for fast RLC error recovery with low latency transmission in accordance with various aspects of the present disclosure. The operations of method 1500 may be implemented by a device such as UE 115 or base station 105, or components thereof, as described with reference to FIGS. 1-9. For example, the operations of method 1500 may be performed by fast RLC error recovery module 510 as described with reference to FIGS. 5-8. In some examples, the device may execute a set of codes to control functional elements of the device to perform the functions described below. In addition or alternatively, the device may perform the aspect functions described below using special purpose hardware. The method 1500 may also incorporate aspects of the methods 1000, 1100, 1200, 1300, and 1400 of FIGS. 10-14.

  [0121] At block 1505, the device may select a fast recovery mode and start a timer, as described herein with reference to FIGS. 2-4, based on the selection. In one particular example, the operation of block 1505 may be performed by a fast recovery mode selector 725, as described herein with reference to FIG.

  [0122] At block 1510, the device may detect a transmission error based on the status of the HARQ process, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1510 may be performed by error detection module 605 as described herein with reference to FIG.

  [0123] At block 1515, the device may start a timer based on the detection of a transmission error, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1515 may be performed by error detection timing module 610, as described herein with reference to FIG.

  [0124] At block 1520, the device may determine that the timer has expired before a grant for retransmission for HARQ processing is received, as described herein with reference to FIGS. 2-4. . In certain examples, the operation of block 1520 may be performed by report trigger module 615, as described herein with reference to FIG.

  [0125] At block 1525, the device may report a transmission error based on the determination, as described herein with reference to FIGS. 2-4. In one particular example, the operation of block 1525 may be performed by error reporting module 620, as described herein with reference to FIG.

  [0126] Thus, the methods 1000, 1100, 1200, 1300, 1400, and 1500 may provide fast RLC error recovery with low latency transmission. Methods 1000, 1100, 1200, 1300, 1400, and 1500 describe possible implementations, and the operations and steps may be rearranged or otherwise performed to allow other implementations. Note that it can be modified. In some examples, aspects from two or more of the methods 1000, 1100, 1200, 1300, 1400, and 1500 may be combined.

  [0127] The description herein provides examples and does not limit the scope, applicability, or examples recited in the claims. Changes may be made in the function and arrangement of the elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. Also, features described with respect to some examples may be combined in other examples.

  [0128] The techniques described herein include code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access. (SC-FDMA), and other systems may be used for various wireless communication systems. The terms “system” and “network” are often used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), and so on. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Release 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA®) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM). The OFDMA system uses wireless technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash OFDM, etc. Can be implemented. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). 3GPP® Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of Universal Mobile Telecommunications System (UMTS) using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and the Global System for Mobile Communications (GSM) are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. The description here, however, describes the LTE system for illustrative purposes, and LTE terminology is used in much of the description above, but the technique is applicable beyond LTE applications. It is.

  [0129] In LTE / LTE-A networks, including such networks described herein, the term evolved Node B (eNB) may generally be used to describe a base station. One or more wireless communication systems described herein may include heterogeneous LTE / LTE-A networks in which different types of eNBs provide coverage for various geographic regions. For example, each eNB or base station may provide communication coverage for a macro cell, a small cell, or other type of cell. The term “cell” is used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (eg, sector, etc.) of a carrier or base station, depending on the context. It is a 3GPP term that can.

  [0130] A base station is referred to as a base transceiver station, a radio base station, an access point, a radio transceiver, a Node B, an eNode B (eNB), a Home Node B, a Home eNode B, or some other suitable terminology. It can be called by a vendor or can include them. The geographic coverage area for the base station may be divided into sectors that constitute only a portion of the coverage area. One or more wireless communication systems described herein may include different types of base stations (eg, macro or small cell base stations). The UEs described herein may be able to communicate with various types of base stations and network equipment, including macro eNBs, small cell eNBs, relay base stations, and so on. There may be overlapping geographic coverage areas due to different technologies.

  [0131] A macro cell generally covers a relatively large geographic area (eg, a few kilometers in radius) and may allow unrestricted access by UEs that are serviced by a network provider. A small cell is a lower power base station that can operate in the same or different (eg, licensed, unlicensed, etc.) frequency band as compared to a macrocell. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell may, for example, cover a small geographic area and allow unrestricted access by UEs that are serviced by a network provider. A femtocell also covers a small geographic area (eg, a house) and has an association with the femtocell (eg, a UE in a closed subscriber group (CSG), a UE for a user in the house) , Etc.) may provide limited access. An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple (eg, two, three, four, etc.) cells (eg, component carriers). A UE may be able to communicate with various types of base stations and network equipment, including macro eNBs, small cell eNBs, relay base stations, and so on.

  [0132] One or more wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations have similar frame timing, and transmissions from different base stations can be roughly aligned in time. For asynchronous operation, the base stations have different frame timings, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operation.

  [0133] The downlink transmissions described herein may also be referred to as forward link transmissions, while uplink transmissions may also be referred to as reverse link transmissions. For example, each communication link described herein, including the wireless communication systems 100 and 200 of FIGS. 1 and 2, may include one or more carriers, where each carrier may include multiple subcarriers (eg, It can be a signal composed of waveform signals of different frequencies. Each modulated signal may be sent on a different subcarrier and may carry control information (eg, reference signal, control channel, etc.), overhead information, user data, etc. The communication link described herein (eg, communication link 125 of FIG. 1) uses frequency division duplex (FDD) operation (eg, using paired spectral resources) or uses TDD operation. (E.g., using unpaired spectrum resources). A frame structure for FDD (eg, frame structure type 1) and a frame structure for TDD (eg, frame structure type 2) may be defined.

  [0134] The description set forth herein in connection with the appended drawings illustrates exemplary configurations and does not represent every example that may be implemented or within the scope of the claims. The term “exemplary” as used herein does not mean “preferred” or “advantageous over other examples”, but “acts as an example, instance, or illustration”. means. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, can be implemented without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

  [0135] In the accompanying drawings, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes between similar components. Where only the first reference label is used herein, the description is applicable to any one of similar components having the same first reference label regardless of the second reference label It is.

  [0136] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or light particles, or any of them. Can be represented by a combination.

  [0137] Various exemplary blocks and modules described in connection with the disclosure herein include general purpose processors, DSPs, ASICs, FPGAs or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, Alternatively, it may be implemented or performed using any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be a combination of computing devices (eg, a combination of a digital signal processor (DSP) and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such Configuration).

  [0138] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored or transmitted as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the present disclosure and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination thereof. . Features that implement functions can also be physically located at various locations, including being distributed such that portions of the functions are implemented at different physical locations. As used herein, including the claims, the term “and / or”, when used in a list of two or more items, It means that any one can be used alone, or any combination of two or more of the listed items can be used. For example, if a configuration is described as including components A, B, and / or C, the configuration may include only A, only B, only C, a combination of A and B, a combination of A and C, A combination of B and C or a combination of A, B and C can be included. Also, as used herein, including the claims, a list of items (eg, “at least one of” or “one or more of” one "or / or" used in a list of items beginning with a phrase such as "or more of)" is, for example, a list of "at least one of A, B, or C" Indicates a disjunctive list such that A, B, C, A and B, A and C, B and C, A and B and C (ie, A, B, and C).

  [0139] Computer-readable media includes both communication media and any non-transitory computer storage media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer readable media includes RAM, ROM, electrically erasable programmable read only memory (EEPROM®), compact disk (CD) ROM or other optical disk storage, magnetic disk storage Can be used to store or carry the desired program code means in the form of an apparatus or other magnetic storage device, or data structure or instructions, accessed by a general purpose or special purpose computer, or a general purpose or special purpose processor Any other non-transitory media that can be played can be provided. Also, any connection is strictly referred to as a computer readable medium. For example, the software uses a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology such as infrared, wireless, and microwave to use a website, server, or other remote source Coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the media definition. Disc and disc, as used herein, are CD (disc), laser disc (registered trademark) (disc), optical disc (disc), digital versatile disc (DVD) (disc), floppy (Registered trademark) disk and Blu-ray (registered trademark) disc, where the disk normally reproduces data magnetically, while the disc is Data is reproduced optically using a laser. Combinations of the above are also included within the scope of computer-readable media.

  [0140] The description herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure should not be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (30)

A wireless communication method,
Detecting a transmission error at a receiving device based at least in part on a state of a hybrid automatic repeat request (HARQ) process;
Starting a timer based at least in part on the detection of the transmission error;
Determining that the timer has expired before a grant for retransmission for the HARQ process is received;
Reporting the transmission error to a transmitting device based at least in part on the determination. Reporting the transmission error is
The method of claim 1, comprising sending an error indication by the receiving device to a radio link control (RLC) entity, a packet data convergence protocol (PDCP) entity, or a medium access control (MAC) entity of the transmitting device. Method.   The method of claim 2, wherein sending the error indication comprises sending the error indication to an entity of the transmitting device using contention based resources. Maintaining a list of unfinished transmissions, wherein reporting the transmission error is based at least in part on the list;
The method of claim 1, further comprising:   The method of claim 4, wherein each entry in the list is mapped to a time index. Reporting the transmission error is
The method of claim 4, comprising sending a bitmap corresponding to the list to the transmitting device.   The method of claim 4, wherein the list is limited to a set of high priority HARQ processes, the HARQ processes being elements of the set of high priority HARQ processes.   8. The method of claim 7, wherein the set of high priority HARQ processes is determined based at least in part on a latency mode of operation. Identifying a new data indicator (NDI) for the HARQ process prior to expiration of the timer, wherein reporting the transmission error is based at least in part on the NDI;
The method of claim 1, further comprising: Selecting a fast recovery mode, wherein starting the timer is based at least in part on the selection;
The method of claim 1, further comprising:   The method of claim 10, wherein the selection is based at least in part on a latency mode of operation.   The method of claim 10, wherein the selection is based at least in part on a configuration of at least one high priority bearer. The method of claim 1, further comprising: sending a negative acknowledgment (NACK) based at least in part on the state of the HARQ process. The method of claim 1, further comprising: maintaining a set of transport blocks in the buffer for a minimum time period for retransmission. A device for wireless communication,
Means for detecting a transmission error at a receiving device based at least in part on a state of a hybrid automatic repeat request (HARQ) process;
Means for starting a timer based at least in part on the detection of the transmission error;
Means for determining that the timer has expired before a grant for retransmission for the HARQ process is received;
Means for reporting to the transmission device the transmission error based at least in part on the determination. The means for reporting the transmission error comprises:
16. The means for sending error indications by the receiving device to a radio link control (RLC) entity, packet data convergence protocol (PDCP) entity, or medium access control (MAC) entity of the transmitting device. apparatus. The means for sending the error indication comprises:
17. The apparatus of claim 16, comprising means for sending the error indication to an entity of the transmitting device using contention based resources. Means for maintaining a list of unfinished transmissions, wherein reporting the transmission error is based at least in part on the list;
The apparatus of claim 15, further comprising:   The apparatus of claim 18, wherein each entry in the list is mapped to a time index. The means for reporting the transmission error comprises:
The apparatus of claim 18, comprising means for sending to the transmitting device a bitmap corresponding to the list.   The apparatus of claim 18, wherein the list is limited to a set of high priority HARQ processes, the HARQ processes being elements of the set of high priority HARQ processes.   23. The apparatus of claim 21, wherein the set of high priority HARQ processes is determined based at least in part on a latency mode of operation. Means for identifying a new data indicator (NDI) for the HARQ process prior to expiration of the timer, wherein reporting the transmission error is based at least in part on the NDI;
The apparatus of claim 15, further comprising: Means for selecting a fast recovery mode, wherein starting the timer is based at least in part on the selection;
The apparatus of claim 15, further comprising:   25. The apparatus of claim 24, wherein the selection is based at least in part on a latency mode of operation.   25. The apparatus of claim 24, wherein the selection is based at least in part on a configuration of at least one high priority bearer. The apparatus of claim 15, further comprising means for transmitting a negative acknowledgment (NACK) based at least in part on the state of the HARQ process. 16. The apparatus of claim 15, further comprising means for maintaining a set of transport blocks in a buffer for a minimum time period for retransmission. A device for wireless communication,
A processor;
Memory in electronic communication with the processor;
Instructions stored in the memory, when executed by the processor, to the device;
Detecting a transmission error at a receiving device based at least in part on a state of a hybrid automatic repeat request (HARQ) process;
Starting a timer based at least in part on the detection of the transmission error;
Determining that the timer has expired before a grant for retransmission for the HARQ process is received;
And an instruction operable to cause a transmitting device to report the transmission error based at least in part on the determination. A non-transitory computer readable medium storing code for wireless communication, the code comprising:
Detecting a transmission error at a receiving device based at least in part on a state of a hybrid automatic repeat request (HARQ) process;
Starting a timer based at least in part on the detection of the transmission error;
Determining that the timer has expired before a grant for retransmission for the HARQ process is received;
A non-transitory computer readable medium comprising instructions executable on a transmitting device to report the transmission error based at least in part on the determination.